NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 22
·13319-13326
·
IF 3.269
Xiuling Xu,Fan Hu,Qi Shuai
Two novel Ba(II) complexes [Ba(TCPA)2(H2O)4] 1 and [Ba(H2O)8]·2(o-FcCOC6H4COO)·6H2O 2 [HTCPA = 2,4,6-trichlorophenoxyacetic acid and o-HOOCC6H4-COFc = o-ferrocenylcarbonyl benzoic acid] have been synthesized by a facile microwave method. The solid-state structures were well established by means of X-ray crystallography as well as routine analysis of the infrared spectrum (FTIR), elemental analysis, field emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TG). Different polyhedra of tricapped triangular prisms for 1 and dodecahedra for 2 were present. It is worth noting that the central Ba(II) ion in 1 is nine-coordinated by two carboxylate oxygen atoms from TCPA ligands and seven oxygen atoms from coordinated water molecules. By contrast, the eight-coordinated Ba(II) in 2 forms barium-water clusters assembled by O–H⋯O hydrogen-bonds contributed by coordinated water molecules. The uncoordinated o-OOCC6H4-COFc ligands in 2 play a key role in the process of charge balance. FESEM images exhibited different surface appearances between the ligand and barium complexes, that is: flower-like HTCPA, branch-like o-HOOCC6H4-COFc, block-like complex 1 and corner-truncated cubes for complex 2. The allelopathic activity of the complexes and their corresponding ligands was evaluated against two herbaceous plants of barnyard grass and turnip (Raphanus sativus). All the tested compounds showed certain activity with good RI values. An antifungal bioassay was also carried out in vitro on three strains of Botrytis cinerea Pers., Glomerella cingulata Schr and Cytospora sp. Complex 1 and HTCPA can work against all three tested fungi, whereas o-HOOCC6H4-COFc and 2 only worked for Botrytis cinerea Pers. The complex presented in this paper has potential applications in weed control, and this work provides an experimental basis for future studies on Ba-based pesticides.
研究领域:
无机化学
·
金属配合物化学
·
农业化学
·
晶体工程
·
植物生理学
·
农药学
·
生物活性评估
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2013
·
IF 3.365
Jing Cuan,Bing Yan
In our work, we achieve the multi-component assembly of novel kinds of photofunctional hybrid materials with polyoxometalates (POMs, Na 9 EuW 10 O 36 ·32H 2 O (EuW 10 O 36 9 - denoted as EuW10)) and benzoate (4-aminobenzoate, 4-hydroxybenzoate, 4-mercaptobenzoate) modified mesoporous silica through imidazolium ionic liquid (IL, 1-methyl-3-(trimethoxysilylpropyl) compound as double functional linkage. Using Pluronic P123 surfactant as a template, benzoate functionalized SBA-15 mesoporous host is synthesized as result of the co-condensation of tetraethoxysilane (TEOS) and benzoate modified siloxane as precursor. We fabricate POM into the framework of functionalized SBA-15 mesoporous silica with IL. Here IL behaves as double linkage, which both interact with PMO with electrostatic force through ion exchange and form covalent bond to the functionalized SBA-15 mesoporous silica through its alkoxy group after cohydroxylysis and copolycondensation process. Tb 3+ is further introduced into the above hybrid system through coordination bond to carboxylate group of benzoate unit, which can be expected to modify luminescence color and to obtain close white luminescence. The physical characterizations prove these hybrid materials possess high surface area, uniform mesoporous structure, good crystallization and relatively excellent luminescence properties.
研究领域:
无机化学
·
材料化学
·
纳米功能材料
·
光物理学
·
配位化学
·
溶胶-凝胶科学
·
稀土发光材料
✓ 已验证
DOI
高影响因子
Journal of Food Measurement and Characterization
·
2020
·Vol. 14
·期 5
·2549-2558
·
IF 1.648
Hu Jun,Liu Yande,He Yong,Sun Xudong,Li Bin
Food safety has been an issue of common concern in today’s society. Excessive benzoic acid (BA) additives in wheat flour would pose a huge threat to human health. In this paper, terahertz (THz) time-domain spectroscopy was used to detect BA quantitatively, which is a preservative additive in flour. Samples were prepared by grinding, drying, weighing, mixing and performing successively according to the designed concentration gradient (concentration 0.04%, 0.08%, 0.1%, 0.2%, 0.4%, 0.5%, 1%, 1.5%, …, 10%), with the BA concentration ranging from 0.040% to 19.99%. Then the THz Spectra of wheat flour samples with different concentrations of BA were collected. After preprocessing the original terahertz spectra with multiple scattering correction and other methods, Competitive Adaptive Reweighted Sampling (CARS), Genetic Algorithm (GA), Principal Component Analysis (PCA) and Uninformative Variable Elimination (UVE) were used to select effective spectral bands, and then Partial Least Squares (PLS) and Least Square Support Vector Machine (LS-SVM) models were established respectively. It turned out that the absorption peak of BA was at 1.94 THz of terahertz absorption coefficient, which increased with the rise of BA concentration. The results also indicated that better modeling results could be obtained by using CARS method for variable selection. And the established CARS-PCA-LS-SVM model had the best prediction result by combining PCA with CARS, with the correlation coefficient of the prediction (R p ) of 0.9956 and Root Mean Square Error of Prediction (RMSEP) of 0.64%. Hence, it can be concluded that terahertz technology combined with LS-SVM model can well achieve the quantitative detection of BA concentration in flour. Although the model is not universal since samples size is not large enough, the research method provides a basis for the detection of BA additives in flour.
研究领域:
食品科学
·
分析化学
·
光谱学
·
食品安全
·
计算生物学
·
分子检测技术
✓ 已验证
DOI
高影响因子
CHROMATOGRAPHIA
·
2018
·Vol. 82
·期 3
·683-693
·
IF 1.401
Shen Chen,Wu Tong,Zang Xiaohuan
In this work, a zeolitic imidazolate framework-based graphene oxide composite (ZIF-8@GO) was prepared and used as the adsorbent in hollow fiber stir bar sorptive extraction. The stir bar was constructed of a small section of hollow fiber filled with 5 mg ZIF-8@GO and a thin stainless wire of 1.5 cm long in its lumen, and used to extract the trace levels of phthalate esters from children’s food samples prior to gas chromatography–mass spectrometric detection. The ZIF-8@GO showed a high adsorption efficiency for the compounds containing aromatic rings. The main experimental parameters that can impact the extraction efficiency including extraction temperature, extraction time, stirring rate, sample salinity, and desorption conditions were investigated. Under the optimized conditions, the limits of detection (LODs) for the five phthalate esters (diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, butylbenzyl phthalate, and di(2-ethylhexyl) phthalate) were 0.15–0.6 µg L −1 for CiCi beverage and pear juice samples, and 0.75–2.2 µg kg −1 for jam samples. The limits of quantitation (LOQs) were 0.5–2.0 µg L −1 for CiCi beverage and pear juice samples, and 2.5–7.5 µg kg −1 for jam samples. Wide linear ranges of 0.5–500.0 µg L −1 and 2.5–2000 µg kg −1 were obtained for CiCi beverage, pear juice samples and jam samples, respectively, with good repeatability (RSD < 11%) and high method recoveries (72%–100%). The lifetime test results showed that the ZIF-8@GO-based hollow fiber stir bar can be reused for 120 extraction cycles without a significant loss of extraction efficiency, indicating its high durability and stability. The established method was applied successfully for the determination of the phthalate esters (PAEs) in children’s food samples. Graphical abstract
研究领域:
分析化学
·
食品安全
·
环境毒理学
·
暴露科学
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食品化学
·
污染物检测
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·Vol. 11
·期 3
·110269
·
IF 7.7
Jinghua Li,Haofeng Zhu,Dandi Fang,Xusheng Huang,Chaoqun Zhang,Ying Luo
Although the recycling and reuse of polyurethane foam (PUF) is a promising route to deal with this type of waste commodity polymer, highly efficient and green processing protocols are a great challenge due to their stable crosslink structure. In this study, a strategy of urethane exchange reactions was proposed to transform commercial rigid PUF into PUF sheets. The process was composed of the pulverization of the foam, the pretreatment method and the hot pressing. The effects of the pretreatment method on the structure and properties of the recycled commercial PUF were studied. The results show that the ball milling pretreatment method can effectively pulverize the commercial PUF into powder of 74.5 µm and a specific surface area as high as 2991.0 m 2 /kg, which can promote the urethane exchange reaction in close contact with the catalyst. The recycle method of ball milling pretreatment makes the crosslink density and tensile strength of the PUF sheets reach 2236.8 mol/m 3 and 32.6 MPa, which means an increase of 9.9 times and 3.3 times, respectively, compared to the method of other pretreatment. Moreover, PUF sheets can still maintain 71.5% of the tensile strength after two cycles of recycling, indicating the potential of this recycling method for PUF. This simple and efficient method enhances the sustainability of rigid PUF utilization and shows the enormous potential for value-added recycling of thermosets .
研究领域:
高分子材料科学
·
环境科学与工程
·
绿色化学
·
资源循环利用
·
材料再生
·
可持续材料技术
·
功能高分子
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2016
·
IF 1.938
Lipeng Wang,Fucheng Zhang,Yongping Bai,Liping Ding
The kinetic of non-isothermal crystallization of Poly (ethylene terephthalate-co-sodium-5-sulfo- iso -phthalate) (PETI) was investigated using differential scanning calorimetry (DSC). Various macrokinetic models namely the Avrami, Tobin, Ozawa, and Ziabicki were used to describe the non-isothermal crystallization process of PETI. Both of the Avrami crystallization rate constant and the Tobin crystallization rate constant were observed to increase with increasing cooling rate. The Avrami model is better than the Tobin model to describe the non-isothermal crystallization process of PETI. The Ozawa crystallization rate K O was found to decrease with increasing cooling rate, while Ziabicki’s kinetic crystallizability parameter G Z was found to increase with increasing cooling rate. The effective energy barrier △E for non-isothermal crystallization process of PETI, analyzed based on the differential iso-conversional method of Friedman, was found to be an increasing function of the relative crystallinity.
研究领域:
高分子化学
·
材料科学
·
物理化学
·
热分析
·
聚合物结晶
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Siyuan Dong,Yingqi Jia,Xiaozhi Xu,Jianeng Luo,Jingbin Han,Xiaoli Sun
Poly(ethylene terephthalate) (PET) generally suffers from low crystallization rate and long molding duration, which as a result limit its application as engineering plastics. To overcome these drawbacks, series of PET/layered double hydroxide (LDH) nanocomposites were prepared by a solution blending process. The effect of metal composition (MgAl and CaAl) and organo-modification (stearic acid intercalated) for LDH fillers on the crystallization behavior of the nanocomposites was investigated. It was revealed that, compared with PET/CaAl-LDH, the PET/MgAl-LDH nanocomposite exhibits a higher crystallization temperature and faster crystallization rate, which is associated with the superior nucleation ability of MgAl-LDH. The nucleation mechanism of PET induced by LDHs was explored by means of Avrami equation and theory of Hoffman-Lauritzen, pointing out that the incorporation of LDHs reduce the free energy of nucleation and the fold surface free energy of PET. In order to improve the compatibility between LDH and PET, stearic acid (SA) intercalated MgAl-LDH was prepared and filled into PET matrix. The resultant PET/MgAl-LDH-SA shows a further enhanced crystallization temperature and accelerated crystallization rate, in comparison with PET/MgAl-LDH nanocomposites. In addition, the thermal stability, gas barrier and mechanical properties of PET/LDH composites were improved upon incorporation of LDH fillers.
研究领域:
高分子科学
·
材料化学
·
纳米复合材料
·
结晶动力学
·
聚合物物理
·
功能材料
·
工程塑料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）